The L3DT map definition (.def.xml) is an XML-based file (using L3DT's XML format spec) that contains the settings used to generate a map, and lists the operations that were performed. These files are automatically saved and loaded along with the map project files, but can also be used to clone a map or generate a batch of maps (see batch generation in the user-guide).
This format replaces the obsolete '.def' format previously used.
See temp1.def.xml